<![CDATA[Current Proteomics (Volume 20 - Issue 3)]]> https://www.eurekaselect.com/journal/70 RSS Feed for Journals | BenthamScience EurekaSelect (+https://www.eurekaselect.com) 2023-12-29 <![CDATA[Current Proteomics (Volume 20 - Issue 3)]]> https://www.eurekaselect.com/journal/70 <![CDATA[Interaction of C-terminal Truncated Beta-amyloid Peptides with Human Serum Albumin]]>https://www.eurekaselect.com/article/1363822023-12-29 Background: The formation of plaque from protein fibrils is the major source of diseases, such as Alzheimer's and Prion diseases. Amyloid beta (Aβ) is a peptide with different lengths, which is one of the main components of the plaque in the brain of people with Alzheimer's. Of the amyloid beta of various lengths in the brain cells plaque, beta-amyloid with 40 amino acids (Aβ1- 40) is more abundant than the rest. Aβ monomers are in a dynamic equilibrium of various conformations with beta sheets that aggregate as oligomers or larger structures. The misfolding of betaamyloid peptide is involved in its accumulation. On the other hand, various species that exist in the cell environment can affect the structure of beta-amyloid peptides.

Aims: This study aimed to study the interaction of truncated forms of beta-amyloid peptide with human albumin serum protein.

Objective: Interaction of beta-amyloid peptide with other proteins is effective in causing Alzheimer's disease. These include interactions between beta-amyloid and cell surface proteins, such as prions and extracellular proteins, such as clusterins and human serum albumin (HSA). As HSA concentrations are higher than other proteins, more than half of the interaction of beta-amyloid with proteins is related to interaction with this protein. Interaction of HSA with beta-amyloid reduces the aggregation of beta-amyloid. However, due to the diversity of beta-amyloid peptides with different lengths, the mechanism of their interaction with HSA has not been well understood. In this work, the interaction of C-terminal truncated beta-amyloid peptides with HSA has been investigated.

Method: The C-terminal truncated forms of beta-amyloid peptides, Aβ1 - 26, Aβ1 - 30, and Aβ1 - 36 and Aβ1 - 40 were designed in silico. Docking between these truncated peptides was performed with serum albumin. A molecular dynamics simulation of the interaction of designed peptides with serum albumin was also performed.

Results and Discussion: The results showed that Aβ1 - 26 and Aβ1 - 30 peptides interact with the interfacial region of the chains A and B of HSA and the surface of the HSA. While the interaction of Aβ1 - 36 and Aβ1 - 40 peptides occurs only with the HSA surface. On the other hand, the interaction of peptides with chain A of HSA is more favorable than their interaction with chain B of HSA. Also, as the length of the peptide increases, the number of residues involved in the hydrophobic interaction increases. The results of molecular dynamics simulation confirm the results obtained from docking.

Conclusion: The results of molecular dynamics and docking simulations show that the binding affinity of peptides to serum albumin decreases with peptide shortening. Also, by changing the structure of beta-amyloid peptides, serum albumin reduces their tendency to aggregate.

]]> <![CDATA[LncRNA SH3BP5-AS1 Regulates the Proliferation and Cell Cycle of Non-Small Cell Lung Cancer Cells]]>https://www.eurekaselect.com/article/1356362023-12-29 Background: Non-small cell lung cancer (NSCLC) consists of a class of heterogeneous diseases.

Objective: LncRNAs are exceedingly implicated in the pathogenesis of NSCLC. Herein, the current study set out to illustrate the molecular mechanism of SH3BP5-AS1 in NSCLC cells.

Methods: SH3BP5-AS1 expression in clinical NSCLC tissues and its impact on prognosis were analyzed by bioinformatics database. SH3BP5-AS1 expression patterns in NSCLC cell lines (A549/H1299/H1975/H460) and human normal lung epithelial cell lines (BEAS-2B) were examined by RT-qPCR. SH3BP5-AS1 was overexpressed in A549 or silenced in H1975 cells through transfection to assess its effect on proliferation, cell cycle distribution, and apoptosis, apoptosisrelated protein (Cleaved Caspase-3, Bax, Bcl-2) levels, invasive, migratory, and healing capacity through CCK-8, colony formation assay, flow cytometry, Western blot, Transwell, and cell scratch test.

Results: SH3BP5-AS1 was under-expressed in NSCLC clinical tissues, and NSCLC patients with low SH3BP5-AS1 expression showed poor prognosis. A549/H1299/H1975/H460 cells had reduced levels of SH3BP5-AS1, with the relative level lowest/highest expression in A549/H1975 cells, respectively. SH3BP5-AS1 overexpression repressed A549 cell proliferation, slowed down cell cycle progression, enhanced apoptosis, elevated Cleared Caspase-3, Bax, suppressed Bcl-2 protein levels, and inhibited migratory, invasive, and scratch healing capacities, while SH3BP5-AS1 silencing brought about the opposite results in H1975 cells.

Conclusion: SH3BP5-AS1 could suppress NSCLC cell proliferation, slow down cell cycle progression, stimulate apoptosis, and limit invasion and migration.

]]> <![CDATA[Knockdown of miR-135a-5p Promotes Mitophagy by Regulating FoxO1/PINK1/Parkin Signaling in Hepatoma Cells Exposed to Oxidative Stress]]>https://www.eurekaselect.com/article/1365942023-12-29 Aim: Consequently, we aimed to explore the role of miR-135a-5p in hepatoma cells (HepG2/3B).

Method: The assessment of protein expression was conducted through western blotting. Furthermore, miR-135a-5p expression was evaluated through RT-qPCR, and apoptosis detection was performed using a flow cytometry assay.

Result: The findings suggest a connection between miR-135a-5p and mitochondrial-driven apoptosis through caspase signaling pathways. Furthermore, miR-135a-5p suppression inhibited the apoptotic response triggered by H2O2, reactive oxygen species (ROS) generation, as well as the decrease in mitochondrial membrane potential.

Conclusion: Additionally, miR-135a-5p knockdown promoted mitophagy by regulating FoxO1/PINK1/Parkin signaling via targeting FoxO1. To conclude, our study implied that miR- 135a-5p might function as a probable regulator that protects cells against oxidative stress.]]> <![CDATA[Protein Profiling of Hirudo orientalis During Different Seasons for Obtaining Accurate Results in Leech Therapy]]>https://www.eurekaselect.com/article/1365502023-12-29 Methods: Protein profiling of salivary gland secretion from leech was studied by SDS-PAGE and 2D Electrophoresis on the proteins with the molecular weight range of 5 - 250 KDa in the lyophilized salivary gland secretion (SGS) during the seasons of summer and winter, and also in the laboratory conditions.

Results: Our results indicated differences in the number and quality of leech saliva proteins in different seasons. We observed a higher number of proteins in summer than in winter. These results demonstrated the presence of Calin and Manillase in summer and Hyaluronidase and Collagenase in winter.

Conclusion: This study could help us in choosing the best and most favorable conditions for using H. orientalis proteins for the treatment of different diseases.]]> <![CDATA[Characterization of a New Hypotensive Peptide from the Venom of Snake Bothrops jararaca (Bj)]]>https://www.eurekaselect.com/article/1365482023-12-29 Aim: The aim of this study is to search for new bioactive peptide/s in the venom of the snake Bothrops Jararaca (Bj).

Objective: The objective is to isolate and characterize new hypotensive peptides from BJ venom.

Methods: We examined the venom of Bj which is known to host a range of bioactive peptides. We have isolated a new peptide (BJ-1) which displayed in vitro potent hypotensive activity. The peptide was purified via Sephadex G25 column chromatography and RP-HPLC. It was characterized by mass spectrometry, amino acid analysis, N-terminal sequencing, and chemical synthesis.

Result: The peptide was identified as an octa-decapeptide with amino acid sequence as DCPSDWSSYEGHCYKPFS where the two Cys residues are likely present in free state, although they can form an internal S-S bond upon oxidation. It was fully confirmed by comparing with synthetic peptide prepared by solid phase chemistry. Both have the same molecular mass (2,108 Da) and identical bioactivity. Furthermore, we rationalize that BJ-1 may be derived from precursor protein “Coagulation factor IX/factor X binding protein (CF-IX/X-BP)” by proteolytic cleavage at the Nterminus of its B-chain within the sequence KPFS18↓E19PKN. This cleavage site contains the recognition motif of enzyme PCSK8 (Proprotein Convertase Subtilisin Kexin8) also known as Subtilisin Kexin Isozyme 1 (SKI-1) or Site 1 Protease (S1P). Despite this observation, using a synthetic peptide encompassing the proposed cleavage site and recombinant PCSK8 enzyme, we found that the enzyme responsible for generation of BJ-1 is not PCSK8. Further studies will be needed to identify the associated enzyme and fully characterize the pharmacological and biological properties of the peptide.

Conclusion: Our study revealed the presence of a novel hypotensive octa-decapeptide in the venom of the snake Bothrops jararaca. It is likely derived from the A-chain of protein CF-IX/X-BP via proteolytic cleavage at the N-terminus by a protease yet to be characterized.]]> <![CDATA[PCM1: A Potential Prognostic Biomarker Correlated with Immune Infiltration in Lung Adenocarcinoma]]>https://www.eurekaselect.com/article/1366052023-12-29 Background: Recent studies have validated the role of Pericentriolar Material 1 (PCM1) in several malignant tumour cell lines, but its specific biological function in lung adenocarcinoma (LUAD) remains unclear.

Objective: To address this gap, this study analyzed 411 LUAD and control samples to evaluate the prognostic value of PCM1 using Cox regression analysis.

Methods: Multiple genes co-expressed with PCM1 were also analyzed to investigate the biological processes and roles involved in PCM1. An endogenous competitive network with PCM1 as the key gene was constructed to uncover its regulatory and competitive relationships in LUAD. The study further explored the immunological characteristics of PCM1 in different expression groups based on immune infiltration analysis.

Results: These findings indicated that higher PCM1 expression levels were associated with better survival prognoses, possibly due to its antagonistic effects on RHOC. Immunological infiltration analysis revealed a significant correlation between PCM1 and various immune cell infiltration levels, including CD4+ T cells, naïve B cells, M2 macrophages, and mast cells. However, there was no significant relationship between PCM1 and MSI, TMB, or stemness, although it was positively correlated with m6A genes. Patients with lower PCM1 expression responded better to CTLA-4 therapy. The study also estimated that some chemotherapeutic and targeted agents might be effective in treating patients with high PCM1 levels. PCM1 was mainly expressed in the cytoplasmic and membranous structures.

Conclusion: PCM1 shows potential as a prognostic biomarker for LUAD due to its strong correlation with immune cell infiltration and its ability to enhance anticancer treatment sensitivity.

]]>